PHARMACOGNOSTIC AND ANTIBACTERIAL STUDIES OF THE LEAVES OF CHROMOLAENA ODORATA (L.) KING & ROBINSON (ASTERACEAE » Download Project Topics

Abstract:

The plant, Chromolaena odorata (L.) King & Robinson is a member of the Asteraceae family. It grows abundantly in Southern Nigeria where its leaves are used as traditional herbal treatment for wounds and fevers. The plant, C. odorata was therefore investigated for antibacterial activities. The leaves of C. odorata were collected from plants growing in their natural habitat in Kaduna State. Standard pharmacognostic methods were used to conduct macroscopic and microscopic studies of the leaf. Physical constants of the leaf were also determined. Furthermore, phytochemical and biological evaluations of the leaf extracts and fractions were conducted. The matured, fresh leaf of C. odorata is green in colour, mildly hairy and deltoid to ovate-lanceolate in shape. The leaf margin is dentate. The leaf measures between 6 – 8 cm in width and 8 – 10 cm in length. The leaf is amphistomatic with anomocytic stomata and non-glandular, uniseriate and multicellular trichomes. The stomata were more in the abaxial surface than in the adaxial with means of 9 ± 1.35 and 3 ± 0.45, respectively. The abaxial surface equally had higher stomatal index of 24.6 % ± 3.69 compared to 7.4 % ± 1.05 for the adaxial surface. Vein islet number and vein termination number were 5.8 ± 0.87 and 4.8 ± 0.72, respectively. The palisade ratio has a mean value of 6.5 ± 0.98. The powdered drug has a moisture content of 9.78 % ± 1.5. The ash value and the acid insoluble ash value were 12.13 % ± 1.82 and 4.11 % ± 0.62 respectively. The alcohol extractive value was 4.87 % ± 0.73, while water extractive value was 3.47 % ± 0.52. The phytochemical study demonstrated the presence of flavonoids, triterpenes, tannins, saponins and anthraquinones in the ethanolic leaf extract. The ethanol ix extract was further partitioned into aqueous, I-butanol and chloroform fractions. Flavonoids and triterpenes were present in all the fractions while tannins were found only in the aqueous and butanol fractions. The chromatographic resolution of ethanolic extract with the solvent system Benzene: Methanol (9:1) showed over 10 spots visible in the daylight. Phytochemical tests indicated that most of the bands represented flavonoids. The ethanol extract and the chloroform, butanol and aqueous fractions showed various degrees of antibacterial activities against Staphylococcus aureus, Streptococcus pyogenes, Salmonella typi and Escherichia coli. The chloroform fraction however, had the most antibacterial activity with the highest zones of inhibition (S. aureus (31 mm), S. pyogene (30 mm), S. typhi (29 mm) and E. coli (29 mm)), lowest minimum inhibitory concentration (MIC) (S. aureus (2.5 mg/ml), S. pyogene (2.5 mg/ml), S. typhi (5 mg/ml) and E. coli (5 mg/ml)) and minimum bactericidal concentration (MBC) (S. aureus (5 mg/ml), S. pyogene (10 mg/ml), S. typhi (20 mg/ml) and E. coli (10 mg/ml)). This study therefore showed that the leaf extract of C. odorata has broad-spectrum antibacterial properties against the common bacteria that infect wounds. This result suggests the scientific reason for the traditional use of the leaf of the plant for wound treatment. Thus, the plant can be an effective and easily accessible herbal drug for the treatment of wounds.

PHARMACOGNOSTIC AND ANTIBACTERIAL STUDIES OF THE LEAVES OF CHROMOLAENA ODORATA (L.) KING & ROBINSON (ASTERACEAE